You'll need patience, some beer and some more patience.
Oh yeah, some choice swear words and more patience.

Not putting down that system or Logic supply, but it's way overpriced.
I did some rough calculations, and I'm putting together a system that is far more capable, draws only slightly more power and will cost a lot less.

A fused line to the battery....?
no gps?
Why XP Home? Pro is better, or even lite for faster booting.
And if your mounting the monitor in the dash, you need beer and patience. and bondo or fiberglass or solvent adhesive plastic.
GOOD LUCK!